MRI Studies on Homunculus Plasticity

Note: The following was written for an in-house Feldenkrais® e-mail list. Yet it is also be of interest for other somatic practitioners.

Robert Schleip, Date: 8/25/99

I just finished reading several reviews of the 9th 'Vienna World Pain Conference' which was conducted last week as a satellite symposium by several international universities. Due to modern imaging methods it has recently become possible to objectify and measure subjective feelings of pain in humans. Some of these newer findings are quite interesting for us as somatic practitioners:

Apparently chronic pain activates similar brain centers as are activated by the mere expectation of pain. Yet acute pain involves additionally some brain centers (e.g. the cerebellum) which are different from those in chronic pain patients. The conclusion seems justified - at least to me - that in the future maybe different therapeutic approaches might be needed for these different kinds of pain. Neurological oriented 're-learning' approaches (i.e. Feldenkrais® work?) seem to be specially valid for chronic pain conditions since these studies have shown that they contain a strong 'learned' component in their neural dynamics.

Concerning chronic pain there were some more specific news: apparently chronic pain leads to changes in the sensory and motor cortex of the brain, both of which are referred to as 'homunculus' (since they have been shown to contain a topographical representation of the body or in other words an internal body image). Based on functional Magnetic Resonance Imaging (fMRI)studies by Herta Flor of the Humbold university of Berlin, chronic back pain tends to lead to an increase of the representational area of the back and spreading into neighboring territory within the homunculus .

Dear Colleagues, this is a very nice hard science confirmation of one of the basic concepts in Feldenkrais work and other somatic practices. Rather than trying to affect the painful tissues by direct local manipulation, our work often focuses on inducing a shift in the internal cortical organization from 'undifferentiated' movements and perceptions towards more 'differentiated' ones. Herta Flor's research now gives us some exciting validation for this approach, at least in chronic back pain patients.

In a joint study with several other universities Flor's team managed to also show that in patients with an amputated arm the representational area of the mouth tends to spread into the cortical area of the missing arm; yet only in those patients which tend to experience phantom pain.

Well, I remember some similar research news from studies by Merzenich (with chimpanzees) and Ramachandran (with humans) several years ago; so these particular new MRI study results are not that surprising. But Flor's team now also showed that usage of prostheses tends to minimize that distortion process within the homunculus and also effectively prevents the development of phantom pain. Now this I find exciting! Who would have thought - lets say 5 years ago - that wearing a prosthesis prevents phantom pain?? What does the prosthesis do to the brain? (or maybe asked differently, what does the brain do with the prosthesis, which it doesn't do without one?)

Some very nice questions for us are triggered by this last finding:

1) Is this just true for amputees and phantom pain, or could we apply a similar therapeutic approach to other pain syndromes and body image distortions?

2) Would the temporary usage of a prosthesis (or an artificial extension of a distal body prominence) work as efficiently for other chronic dysfunction? E.g. exploratory movements with a paper tailbone extension for low back pain (or how about playing with an artificial elbow extension for shoulder problems, or 'top of the head'-extensions for cervical dysfunction's?). It would be neat to measure these with similar MRI measurements of the homunculus activation.

3) Would an imaginary limb extension work as effective as a real one? (as we often work with imaginary ones in our Feldenkrais lessons)

4) Would it be possible to sharpen the design of our lessons to work even more with this neural mechanism for some chronic pain patients?

5) And finally: How often or how long does one need to play with these lessons in order to lead to a measurable shift in the shape of the homunculus?

I would not be surprised if these new types of computerized brain imaging studies could allow us to gain some answers (and new questions ;-) in the coming years.